Method for reducing or preventing the establishment, growth or metastasis of cancer by administering PAR-1 and optionally PAR-2 antagonists

ABSTRACT

We have discovered a method of modifying the tumor cell microenvironment to reduce or prevent the establishment, growth or metastasis of malignant cells comprising administering to a patient having malignant cells a pharmaceutically effective amount of a PAR-1 inhibitor and optionally a PAR-2 inhibitor to prevent or reduce activation of normal cells within the tumor microenviroment. This method also has the effect in some patients of modulating the immune system to facilitate a more efficient immune response to malignant cells and maybe coupled with cytokine therapy and T-cell therapy to enhance the patient&#39;s immune response to the malignant cells.

[0001] This invention is a continuation-in-part of serial number 09/603,229 filed on Jun. 26, 2000 and claims benefit of serial number 60/141,555 filed on Jun. 29, 1999 (both hereby incorporated by reference). This invention relates to the use of PAR-1 antagonist and optionally PAR-2 antagonist to reduce or prevent the establishment, growth and/or metastasis of malignant cells, as well as, immune modulation to aid in the treatment of malignant cells.

BACKGROUND OF THE INVENTION

[0002] Malignant cells solicit the help of other cell types such as stromal fibroblasts, mast cells, monocytes and vascular cells, to facilitate their invasion into the surrounding tissue (Gregoire and Lieubeau, 1995) because unrestrained growth of the tumor, by itself, does not result in invasion and metastasis (Liotta et al., 1991). The interface between the invading malignant cells and the hosting stromal cells, referred to as the tumor microenvironment (TME) (O'Meara, 1958), possesses a vast array of well-orchestrated cell signaling molecules which function to facilitate the proliferating tumor front to invade the stroma, degrade and remodel the extracellular matrix and so forth (Gregoire and Lieubeau, 1995). Of the many factors secreted by the tumor cells, the two proteolytic enzymes, thrombin and trypsin, have been correlated to the stage and type of carcinoma and are associated with cell invasion and extracellular matrix degradation (Koivunen et al., 1991). Furthermore, the ratio of proteases to their inhibitors in the TME can favor capillary sprout elongation and lumen formation during angiogenesis (Liotta et al., 1991).

[0003] Thrombin is known for example to facilitate metastasis, stimulate the adherence of platelets, increase vascular permeability, attract monocytes, stimulate mitogenic activity of endothelial cells and fibroblasts, degranulate mast cells (Fenton et al., 1995; Vouret-Craviari et al., 1992 ; Carney, 1992; Nierodzik et al., 1992 & 1996; Wojtukiewicz et al., 1993 & 1995; Cirino et al., 1996; Razin and Marx, 1984). Thrombin also influences the rate of deposition of connective tissue proteins and the development of tissue fibrosis during normal wound healing; a process similar to cellular metastasis (Chambers et al., 1998). Many of thrombin's effects are mediated through a seven transmembrane G-protein coupled receptor known as protease-activated receptor-1 (PAR-1) via proteolytic cleavage of the amino-terminal extension unveiling a new amino terminus that folds back on the receptor thereby activating the receptor as a tethered peptide ligand (Vu et al., 1991). Thrombin and PAR-1 agonist peptides promote tumor cell adhesion to endothelium, extracellular matrix and platelets, enhance the metastatic capacity of tumor cells, activate cell growth and stimulate angiogenesis (Nierodzik et al., 1992 & 1995; Dennington and Bemdt, 1994; Klementsen and Jorgensen, 1997; Wojtukiewicz et al., 1993 & 1995; Tsopanglou et al., 1997; Mirza et al., 1996). PAR-1 has been localized in pancreas tumor cells (Rudroff et al., 1998), carcinoma and melanoma cell lines (Wojtukiewicz et al., 1995). In breast carcinoma cells, the level of PAR-1 expression has been correlated to the degree of invasiveness (Even-Ram et al., 1998). Furthermore, B16F10 melanoma cells, transfected with PAR-1, enhanced thrombin-treated tumor cell adhesion to fibronectin 2.5-fold in vitro and pulmonary metastasis as high as 39-fold in vivo compared to the control thrombin-treated tumor cells (Chen et al., 1998). However, the expression of PAR-1 in malignant and benign human tumor tissues has not been extensively described in their histological context among the surrounding cell types forming the TME.

[0004] Trypsin can stimulate fibroblasts to secrete procollagen, stimulate mast cells to degranulate and is secreted by numerous tumor cell lines that are correlated with the stage and histological type of carcinoma (Koivunen et al., 1991; Koshikawa et al., 1992 & 1994; Hirahara et al., 1995). Some of the actions of trypsin are mediated by a second protease-activated receptor known as PAR-2 (Nystedt et al., 1994; Bohm et al., 1996; Mizra et al., 1996; Hollenberg et al., 1996) which has been described in human tissues and tumor cell lines (Nystedt et al., 1994; Bohm et al., 1996; D'Andrea et al., 1998). Trypsin's ability to degrade matrix proteins suggests it may participate in the processes of invasion, adhesion and metastasis; however, the presence of trypsin in tumors also suggests that PAR-2 may mediate these processes (Miyata et al., 2000). Although it is clear that tumor-derived trypsin-like enzymes could directly regulate growth in an autocrine and/or paracrine manner via PAR-2 activation (Bohm et al., 1996), the function of PAR-2 activation in metastasis has not been described.

[0005] Since both thrombin and trypsin appear to activate several immune cells including monocytes/macrophages and mast cells. Monocytes/ macrophages and mast cells may play a significant role in facilitating the survival, growth and metastasis of malignant cells. The role of monocyte infiltration in tumors is somewhat controversial. In some circumstances monocyte infiltration has been associated both with inhibiting tumor growth and in other circumstances with stimulating tumor growth. However, if the macrophages/monocytes have been activated they will produce reactive oxygen species that will lead to the decreased expression of CD3ζ and results in reduced T cell response to tumor cells (Otsuji et al., 1996). The activation and degranulation of mast cells is associated with the expression of Th2 cytokines (e.g. IL-4, IL-10, IL-13) and growth factors (e.g. TFG-β) that would lead be expected to lead to the recruitment of other immune cells (i.e. CD4 T cells etc.) and the development of a localized Th2 type immune response (Bradding et al., 1995; Moller et al. 1998). One consequence of a localized Th2 immune response being established is the localized suppression of Thl cytokine expression. Unfortunately, the Th1 cytokines are associated with the activation of cytolytic T cells (CTL) and natural killer cells (NK cells), which are believed to be the principle cells that the immune system uses in attempting to respond to the presence of malignant cell and in limiting their growth and metastasis. Studies in animals have demonstrated that IL-4 will suppress T lymphocytes from tumor draining lymph nodes in vivo (Fu et al., 1997). Similarly, the expression of IL-10 also appears to block the generation of a tumor specific Th1 immune response (Halak et al., 1999). In human patients with various cancers the mean level of IL-4 seems to be elevated and the levels of cytokines associated with Th1 response are significantly reduced as compared to healthy subjects (Goto et al., 1999). The growth factors secreted by mast cells also may play a role in immune suppression. TGFβ appears to suppress T cell response to tumors (Jarnicki et al. 1996). Additionally, mast cells degranulation will release among other things neutral proteases such as tryptase (which cleaves fibrinogen and activates collagenase) and chymase (which converts angiotensin I into angotensin II and degrades basement membranes). Chymase also appears to activate MMP-9/gelatinase B, which also cleaving the IL-2Rα receptor of T cells down regulating the capability of T cells to proliferate in the tumor microenvironment in response to IL-2 (Coussen et al., 1999; Sheu et al., 2001). The presence of these enzymes in the TME should facilitate the colonization, growth, and potentially the metastasis of malignant cells.

[0006] We have discovered the presence of PAR-1 and PAR-2 in the stromal fibroblast and mast cells are important in establishing a TME that facilitates the metastasis of cancer cells. Therefore, it is an object of the present invention to provide (1) a method of modifying the tumor cell microenvironment to reduce or prevent the establishment, growth or metastasis of certain types of malignant cells; and (2) a means of modulating the immune system to more effectively respond to malignant cells.

SUMMARY OF THE INVENTION

[0007] We have discovered a method of modifying the tumor micro environment to reduce or prevent the establishment, growth or metastasis of malignant cells that activate the PAR-1 receptor of normal cells comprising providing a pharmaceutically effective amount of a PAR-1 inhibitor and optionally a PAR-2 inhibitor to a patient with malignant cells.

[0008] In another embodiment of the present invention we have discovered a method for the modulation of the immune system to facilitate a more efficient immune response to malignant cells that activate the PAR-1 receptor comprising administer a pharmaceutically effective dose of a PAR-1 inhibitor and optionally a PAR-2 inhibitor to a patient to enhance the patient's immune response to the malignant cells.

BRIEF DESCRIPTION OF THE FIGURES

[0009]FIG. 1. Is a graphic illustration of PAR-1 and PAR-2 immunolabeling in normal (n=20), benign (n=10) and malignant (n=46) human breast tissues. Immunolabeling data was expressed as the mean±S.E. Intesity of labeled cells observed in a 20x viewing field the following values were assigned to cells; (0.0) was assigned to unlabeled cells; (1.0) was assigned to weak or light brown labeling; (2.0) was assigned to moderate brown labeling; and (3.0) was assigned to intense or dark brown labeling.

[0010]FIG. 2. Presents representative immunohistochemical micrographs for normal (left panels: A, D, G, J), benign (middle panels: B, E, H, K) and malignant (right panels: C, F, I, L) breast tissues are presented in FIG. 2. Breast tissues were assayed for inununohistochemistry using negative control antibodies A-C, smooth muscle actin antibodies (D-F), DNA topoisomerase Ia antibodies (G-I), PAR-1 (J-L) antibodies, and PAR-2 (M-O) antibodies. Arrowheads indicate normal, benign and malignant epithelial cells in the breast. Arrows indicate areas in labeling in the stromal fibroblasts. Mast cells (MC) and macrophages (M) are indicated in the tissue. The magnification was approximately 900x.

[0011]FIG. 3. Presents representative immunohistochemical micrographs of PAR-1(A, C, E) and PAR-2 (B. D, F) expression observed in gastric carcinoma (A, B), undifferentiated carcinoma (C, D) and lung adenocarcinoma (E, F) tissues. Arrowheads indicate positive immunolabeling in tumor cells and arrows indicate immunolabeling in the stromal fibroblasts. The magnification was approximately 900x.

[0012]FIG. 4. Human malignant breast carcinoma tissues were assayed for the expression of PAR-1 (A) and PAR-2 (B) mRNA through in situ hybridization. The positive control probe, GAP-DH (C) and the negative control probe lac Z (D) are also presented. Arrowheads indicate tumor cells and arrows indicate stromal fibroblasts. The magnification was approximately 900x.

[0013]FIG. 5. Presents representative immunohistochemical micrographs of malignant breast tissues processed using double immunohistochemical procedures for detecting the presence of PAR-1 (brown) and Topo IIα (red) and PAR-2 (brown) and Topo IIα (red). Arrowheads indicate the presence of proliferating, red-labeled nuclei cells with the presence of brown intracellular and membrane PAR-1 and PAR-2 positive cells. The magnification was approximately 900x.

[0014]FIG. 6. Presents representative irnmunocytochemical micrographs for quiescent (A, D, G, J, M), proliferating (B, E, H, K, N) and wounded (C, F, I, L, O) human dermal fibroblasts using negative control antibodies (A-C), antibodies to detect smooth muscle actin (SMA) (D-F), Topo IIα (G-I), PAR-1 (J-L) and PAR-2 (M-O). No observable labeling was observed of cells using negative control antibodies. No SMA immunolabeling was not observed in the quiescent cultured cells (D). SMA-positive cells (arrowheads) were observed in cultured cells in the proliferating and wounding conditions (E-F). Proliferating cells were detected by the presence of brown, Topo IIα-positive nuclei in the proliferating cells (H-I), but not in the quiescent cells (G). Positive intracellular and membrane PAR-1 (K-L) and PAR-2 (N-O) immunoreactive cells (arrowheads) were observed in the cells in the proliferating and wounding conditions, but were absent in the cells in the quiescent cells for PAR-1 (J) and PAR-2 (M). The magnification was approximately 900x.

DETAILED DESCRIPTION OF THE INVENRION

[0015] We have discovered that the activation of PAR1 and/or PAR2 on normal host cells appears to participate in creating an environment that allows malignant cells to become established, grow or metastasize. This activation is associated with a variety of cells that form the TME such as fibroblasts, mast cells and macrophages/monocytes. PAR-1 and PAR-2 activation of the stromal fibroblasts is believed to contribute to the elaboration of mitogens for angiogenesis and tumor cell growth. This activation is also believed to result in the deposition of extracellular matrix proteins and the release of proteolytic enzymes to facilitate tumor growth and metastasis. The activation of PAR-1 and/or PAR-2 on monocytes/macrophages is also appears to potentially suppress CTL and NK cells that would other wise mount an immune response to the tumor cells. The activation of PAR1 and/or PAR2 receptors of mast cells is also believed to result in the establishment of an inappropriate immune response to malignant cells. This activation appears to lead to an autocrine activation cycle of PAR1 and/or PAR2.

[0016] Administering a PAR1 antagonist will block the activation and degranulation of mast cells in response to thrombin and other activator of PAR1. Co-administration of PAR-1 and PAR2 antagonists is anticipated to further reduce the potential for the activation and degranulation of mast cells in response to thrombin and other direct or indirect activators of PAR1 and PAR2 (e.g. trypsin). Additionally, cytokines and other therapeutic agents may be simultaneously or sequentially administered to facilitate a desired immune response to the malignant cells such as the activation of CTL and NK cell, activation of cytolytic T lymphocytes or stimulation of antigen presenting cells. Generally the cytokines will be those that are associated with establishing a Th1 response such as IL-2, IL-12 and IL-18.

Diagnosis

[0017] Suspected malignant cells and surrounding tissue may be isolated by well-known surgical techniques (such as needle biopsy). The suspected malignant cells maybe tested for the secretion of substances that activate PAR1 and/or PAR2. Some of the proteins that are known to activate PAR-1 are thrombin and trypsin. Suitable means for testing for these proteins include but are not limited to bioassay or pathologic analysis of tissue specimens. The presence, type and relative concentration of these proteins will allow for the qualification of these malignant cells for mast cell activation and degranulation consequently the potential for metastasis. Additionally the surrounding fibroblast tissue may be tested for the relative amounts of PAR-1 and PAR-2 to determine the tumor grade and determine its degree of malignancy.

Method for Reducing or Preventing Metastasis

[0018] Since, PAR-1 and PAR-2 are directly implicated in the cascade of events leading to metastasis of malignant cells expressing PAR-1 and PAR-2 activator proteins blocking this process would disrupt the process of malignant cell metastasis. Consequently, the use of PAR-1 and PAR-2 antagonist and the like (e.g. antisense sequences), receptor blocking ligands or antibodies, or the use of anti-thrombin and anti-tryptase agents would provide a means of reducing or preventing metastasis.

[0019] Suitable PAR-1 antagonist include antibodies that block activation of PAR-1 receptor and compounds of the general formula:

[0020] wherein:

[0021] R¹ is selected from amino, C₁-C₈ alkylarnino, C₁-C₈ dialkylamino, arylamino, arC₁-C⁸ alkylamino, C₃-C⁸ cycloalkylamino, heteroalkyl C₁-C₈ alkylamino, heteroalkyl C₁-C₈ alkyl-N-methylamino, C₁-C₈ dialkylamino C₁-₈ alkylamino, -N(C₁-C₈alkyl)-C₁-C₈alkyl-N(C₁-C₈alkyl)₂, -N(C₁-C₈ alkyl) (C₁-C₈ alkenyl), -N(C₁-C₈alkyl)(C₃-C₈cycloalkyl), heteroalkyl or substituted heteroalkyl, wherein the substituent on the heteroalkyl is selected from oxo, amino, C₁-C₈ alkoxy, C₁-C8 alkyl, C₁-C₈ alkylamino or C₁-C₈ dialkylamino;

[0022] R₂ is selected from unsubstituted or substituted aryl, arC₁-C₈ alkyl, C₃-C₈cycloalkyl or heteroaryl, wherein the substituents on the aryl, aralkyl, cycloalkyl or heteroaryl group are independently selected from one or more of halogen, nitro, amino, cyano, hydroxyalkyl, C₁-C₈ alkyl, C₁-C₈ alkoxy, C₁-C₈alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl;

[0023] R₃ is selected from H or C₁-C₈ alkyl;

[0024] R₄ and R₅ are each selected from H, C₁-C₈ alkyl, amino C₁-C₈ alkyl, amidino C₁-C₈ alkyl, guanidino C₁-C₈ alkyl, aryl, aryl C₁-C₈ alkyl, substituted aryl, substituted arylC₁-C₈ alkyl, heteroaryl, heteroaryl C₁-C₈ alkyl, substituted heteroaryl, substituted heteroaryl C₁-C₈ alkyl, cyclo C₃-C₆ alkyl or substituted cycloC₃-C₆alkyl, wherein the substituents on the aryl, aralkyl, cycloalkyl or heteroaryl group are independently selected from one or more of halogen, nitro, amino, amidino, guanidino, cyano, hydroxyalkyl, C₁-C₈ alkyl, C₁-C₈ alkoxy, C₁-C₈ alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl;

[0025] R₆ and R₇ are each selected from H, C₁-C₈ alkyl, amino- C₁-C₈ alkyl, amino- C₃-C₈ cycloalkyl, amidino C₁-C₈ alkyl, guanidino C₁-C₈ alkyl, aryl, substituted aryl, aryl C₁-C₈ alkyl, substituted aryl C₁-C₈ alkyl, heteroaryl C₁-C₈ alkyl or substituted heteroaryl C₁-C₈ alkyl, wherein the substituents on the aryl, aralkyl, cycloalkyl or heteroaryl group are independently selected from one or more of halogen, nitro, amino, amidino, guanidino, cyano, hydroxyalkyl, C₁-C₈ alkyl, C₁-C₈ alkoxy, C₁-C₈ alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl;

[0026] Either R₅ or R₇ must be H when m is 1; in addition, when R₅ is H, then R₄ cannot be H; and, when R₇ is H, then R₆ cannot be H;

[0027] R₈ is selected from H, C₁-C₈ alkyl, amino C₁-C₈ alkyl, allyl, C₃-C₈ cycloalkyl, substituted C₃-C₈ cycloalkyl, aryl, substituted aryl, ar C₁-C₈ alkyl, substituted ar C₁-C₈ alkyl, heteroaryl, substituted heteroaryl, heteroaryl C₁-C₈ alkyl or substituted heteroaryl C₁-C₈ alkyl, wherein the substituents on the aryl, aralkyl, cycloalkyl or heteroaryl group are independently selected from one or more of halogen, nitro, amino, amidino, guanidino, cyano, hydroxyalkyl, C₁-C₈ alkyl, C₁-C₈ alkoxy, C₁-C₈ alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl;

[0028] X is CH or N;

[0029] n is an integer selected from 0, 1, 2 or 3;

[0030] m is an integer selected from 0 or 1;

[0031] p is an integer selected from 1 or 2;

[0032] and pharmaceutically acceptable salts thereof.

[0033] In one embodiment of the invention is the compound of formula (I) wherein

[0034] R₁ is selected from dimethylamino, diethylamino, di-(n-propyl)amino,

[0035] R₂ is selected from unsubstituted or substituted aryl, arC₁-C₆ alkyl, C₃-C₆ cycloalkyl or heteroaryl, where the substituents on the aryl, aralkyl, cycloalkyl or heteroaryl group are independently selected from one to three substituents selected from halogen, cyano, C₁-C₄ alkyl, C₁-C₄ alkoxy, C₁-C₄ alkoxycarbonyl, fluorinated CN-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl; preferably, R₂ is unsubstituted or substituted phenyl wherein the substituent is one or two substituents selected from fluorine, chlorine, iodine, methyl, cyano or trifluoromethyl;

[0036] R₃ is selected from H or C₁-C₄ alkyl; preferably, R₃ is H;

[0037] R₄ and R₅ are each independently selected from H, C₁-C₄ alkyl, aminoC₁-C₆ alkyl, amidinoC₁-C₆ alkyl, guanidinoC,-C₆ alkyl, aryl, arC₁-C₈ alkyl, substituted aryl, or substituted arC₁-C₈ alkyl, where in the substituents on the aryl or aralkyl are independently selected from one or tw o of halogen, nitro, amino, as idino, guanidino, cyano, hydroxyalkyl, C₁-C₆ alkyl, C₁-C₆ alkoxy, C₁-C₆ alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl;

[0038] R₆ and R₇ are each independently selected from H, C₁-C₄ alkyl, aminoC,-C₆ alkyl, amidinoC₁-C₆ alkyl, guanidinoC₁-C₆ alkyl, aryl, substituted aryl, arC₁-C₆ alkyl, substituted arC₁-C₆ alkyl, C₃-C₆ cycloalkylC₁-C₆ alkyl, heteroarylC₁-C₆ alkyl or substituted heteroarylC₁-C₆ alkyl, wherein the substituents on the aryl, aralkyl, or heteroaryl group are independently selected from one or two of halogen, nitro, amino, amidino, guanidino, cyano, hydroxyalkyl, C₁-C₆ alkyl, C₁-C₆ alkoxy, C₁-C₆ alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl;

[0039] preferably, R₄, R₅, R₆, and R₇ are each independently selected from H, aminoC₁-C₅ alkyl, amidinoC₁-C₅ alkyl, guanidinoC₁-C₅ alkyl, C₃-C₆ cycloalkylC₁-C₆ alkyl, heteroarylC₁-C₆ alkyl, benzyl or substituted benzyl wherein the substituents on the benzyl are independently selected from one or two of chlorine, fluorine, methyl or trifluoromethyl;

[0040] R₈ is selected from H, C₁-C₆ alkyl, aminoC₁-C₆ alkyl, aryl, substituted aryl, arC₁-C₆ alkyl, or substituted arC₁-C₆ alkyl, wherein the substituents on the aryl or aralkyl group are independently selected from one or more of halogen, nitro, amino, amidino, guanidino, cyano, hydroxyalkyl, C₁-C₆ alkyl, C₁-C₆ alkoxy, C₁-C₆ alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl; preferably, R₈ is benzyl;

[0041] n and p are both 1;

[0042] provided that when m is one, then one of R₅ or R₇ must be hydrogen;

[0043] and provided further that when R₅ is hydrogen, then R₄ cannot be hydrogen; and, when R₇ is hydrogen, then R₆ cannot be hydrogen; and pharmaceutically acceptable salts thereof.

[0044] In a class of the invention is the compound wherein

[0045] R₂ is 2,6-dichlorophenyl;

[0046] and all other variables are as defined above;

[0047] provided that when m is one, then one of R₅ or R₇ must be hydrogen;

[0048] and provided further that when R₅ is hydrogen, then R₄ cannot be hydrogen; and, when R₇ is hydrogen, then R₆ cannot be hydrogen; and pharmaceutically acceptable salts thereof. These compounds will be described more fully hereinafter.

[0049] Suitable PAR-2 antagonists include antibodies that block activation of the PAR-2 receptor and antisense sequences that hybridize to uniquely conserved regions of the PAR-2 protein. Suitable antisense sequences include the SLIGKV sequence of nucleotides 38-43. A description of these antisense sequences may be found in WO 00/8150 published Feb. 1, 2000 hereby incorporated herein by reference.

[0050] Suitable antibodies for the PAR-1 and the PAR-2 receptors that block activation of these receptors can be readily developed using conventional monoclonal or polyclonal technology. PAR-1 (Smith-Swintosky et al., 1997; Cheung et al., 1999; Festoff et al., 2000) and PAR-2 (Smith-Swintosky et al., 1997;

[0051] D'Andrea et al., 1998; Damiano et al., 1999) antibodies have been previously described and characterized. This antibodies would have to be tested for the presence of crossreative species and the cross reactive species removed by appropriate techniques (e.g. using the crossreactive antigen bound to columns to extract the cross reactive species). Additionally, antibodies effectiveness in blocking PAR-1 and PAR-2 activation would have to be monitored.

[0052] The daily dosage of the PAR-1 and/or PAR-2 antagonist may be varied over a wide range from about 0.01 mg to about 1,000 mg per adult human per day. For oral administration of PAR-1 antagonist, the compositions are preferably provided in the form of tablets containing about 0.01, 0.05, 0.1, 0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0, 50.0, 100, 150, 200, 250 and 500 mg of the active ingredient for the symptomatic adjustment of the dosage to the patient to be treated. An effective amount of the drug is ordinarily supplied at a dosage level of from about 0.03 mg/kg to about 100 mg/kg of body weight per day. Preferably, the range is from about 0.1 mg/kg to about 30 mg/kg of body weight per day. The compounds may be administered on a regimen of about 1 time to about 4 times per day.

[0053] Optimal dosages to be administered may be determined by those skilled in the art. Since each malignant cell line will differ it is expected that the physician treating the patient will have to vary the dosage of the particular compound used, depending on the mode of administration, the strength of the preparation, the physical condition of the patient and the advancement of the disease condition. In addition, factors associated with the particular patient being treated, including patient age, weight, diet and time of administration, will result in the need to adjust dosages. Response to the treatment may be monitored by conventional means including by CAT scan, MRI, ultrasound or other imaging techniques.

Immune Modulation

[0054] To restore the immune modulation disrupted in the TME pharmaceutically active compounds maybe administered prior to, concurrently with, or subsequent to, the administration of PAR-1 and/or PAR-2 antagonists to deactivate mast cells and/or activate CTL or NK cells. Suitable cytokines include but are not limited to interleukin-2 (IL-2), interleukin-12 (IL-12 ) interleukin-18 (IL-18), granulocyte colony stimulating factor (G-CSF), macrophage colony stimulating factor (-CSF), granulocyte-macrophage colony stimulating factor (GM-CSF), interferon alpha, interferon beta, interferon-ganuna, tumor necrosis factor (TNF) and combinations thereof. Generally, a pharmaceutically effective amount of an cytokines will be in the range of from about 1,000 to about 3,000,000 U/kg/day; more preferably in an amount of from about 3,000 to about 1,000,000 U/kg/day; and more preferably in an amount from about 5,000 to about 20,000 U/kg/day.

[0055] Other methods of enhancing the immune response to malignant cells have been described in the art such as enhancing the activation of NK cells which was described by Hellstrand et al. in U.S. Pat. No. 6,071,509 (hereby incorporated by reference herein). Similarly, T cell activation can be used as a means of treating cancer. T cell can be activated by isolating tumor infiltrating autologous T cells, activating the T-cells in vitro with IL-2, allowing the T cells to proliferate and injected into the patient. Additionally, T cells activity can be increased by utilizing blocking antibodies against CTLA-4 as described by E.D. Kwon et al., Proc. Natl. Acad. Sci. U.S.A. 94, 8099 (1997) and Allison et al. in U.S. Pat. No. 6,051,227 (hereby incorporated by reference herein). Similarly antiCD3 and antiCD28 and B-7 may also be employed to enhance the immune response.

Therapeutic Use

[0056] PAR-1 and/or PAR-2 antagonist may be used in subjects having malignant cells that characteristically activate fibroblasts, monocytes/macrophages, mast cells and combinations thereof. Generally malignant cell that secrete proteases or otherwise directly or indirectly activate the PAR-1 and/or PAR-2 receptors in the TME maybe treated by the present therapy. Representative malignant cell types characteristically associated with fibroblasts, monocytes and/or mast cells include but are not limited to lung cancer (e.g. non-small-cell lung cancer), skin cancer (e.g. melanomas), stomach cancer, intestinal cancer, colorectal cancer, pancreatic cancer, liver cancer, thyroid cancer, uterine cancer, cervical cancer, ovarian cancer, testicular cancer, prostrate cancer and breast cancer.

[0057] The use of PAR-1 and/or PAR-2 antagonist to reduce or prevent metastasis maybe employed as soon as malignant cells are detected with or without immune modulation techniques or conventional therapeutic methodologies (e.g. chemotherapy agents or radiation). Suitable chemotherapy agents include but are not limited to anti-angiogenic compounds, alkylating compounds, antimetabolites, hormonal agonist /antagonists, monoclonal antibodies for cancer treatment, antiproliferatives, etc. and combinations thereof. Any anti-angiogenic compound can be used. Exemplary anti-angiogenic compounds include O-substituted fumagillol and derivatives thereof, such as TNP-470, described in U.S. Pat. Nos. 5,135,919, 5,698,586, and 5,290,807 to Kishimoto, et al. (hereby incorporated by reference herein); angiostatin and endostatin, described in U.S. Pat. Nos. 5,290,807, 5,639,725 and 5,733,876 to O'Reilly (hereby incorporated by reference herein); thalidomide, as described in U.S. Pat. Nos. 5,629,327 and 5,712,291 to D'Amato (hereby incorporated by reference herein); and other compounds, such as the anti-invasive factor, retinoic acid, and paclitaxel, described in U.S. Pat. No. 5,716,981 to Hunter, et al., (hereby incorporated by reference herein)and the metalloproteinase inhibitors described in U.S. Pat. No. 5,713,491 to Murphy, et al (hereby incorporated by reference herein). Other well known chemotherapeutic agents may also be used such as doxorubicin, decarbazine, irinotecan, etoposide phosphate, asparaginase, gemcitabine, carboplatinum, cisplatinum, tomoxifen, methotrexate, ifosfamide, cyclophosphamide, 5-fluorouracil, vinorelbine tartrate, anastrozole, trastuzumab and combinations thereof. These and other chemotherapeutic agents for the treatment of cancer may be found in the Physicians Desk Reference (hereby incorporated by reference herein).

[0058] The method of prevention or reduction of the establishment, growth and/or metastasis of malignant cells may be used preoperatively and post-operatively as an adjunct to surgery.

Dosage

[0059] It is contemplated by this invention that the administration of the compositions described herein for reducing or preventing metastasis or immune modulation may be accomplished by any of the methods known to the skilled artisan. The compound may be administered to a patient by any conventional route of administration, including, but not limited to, intravenous, oral, subcutaneous, intramuscular, intradermal and parenteral. The compounds used in reducing or preventing metastasis or immune modulation will generally be provided in association with a pharmaceutically acceptable carrier recognized as suitable by those skilled in the art.

[0060] The term “subject” as used herein, refers to an animal, preferably a mammal, most preferably a human, who has been the object of treatment, observation or experiment.

[0061] It is understood that the dosage of a pharmaceutical compound or composition of the present invention administered in vivo or in vitro will be dependent upon the age, sex, health, and weight of the recipient, kind of concurrent treatment, if any, frequency of treatment, and the nature of the pharmaceutical effect desired. The ranges of effective doses provided herein are not intended to be limiting and represent preferred dose ranges. The most preferred dosage will be tailored to the individual subject, as is understood and determinable by one skilled in the relevant arts. See, e.g., Berkow et al., eds., The Merck Manual, 16th edition, Merck and Co., Rahway, N.J. (1992); Goodman et al., eds., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th edition, Pergamon Press, Inc., Elmsford, N.Y. (1990); Avery's Drug Treatment: Principles and Practice of Clinical Pharmacologv and Therapeutics, 3rd edition, ADIS Press, LTD., Williams and Wilkins, Baltimore, Md. (1987); Ebadi, Pharmacology, Little, Brown and Co., Boston (1985); Osol et al., eds., Remington's Pharmaceutical Sciences, 17th edition, Mack Publishing Co., Easton, Pa. (1990); Katzung Basic and Clinical Pharmacology, Appleton and Lange, Norwalk, Conn., (1992), which references are entirely incorporated herein by reference. The term “therapeutically effective amount” as used herein, means that amount of active compound or pharmaceutical agent that elicits the biological or medicinal response in a tissue system, animal or human that is being sought by a researcher, veterinarian, medical doctor or other clinician, which includes alleviation of the symptoms of the disease or disorder being treated.

[0062] The total dose required for each treatment can be administered by multiple doses or in a single dose. The diagnostic/pharmaceutical compound or composition can be administered alone or in conjunction with other diagnostics and/or pharmaceuticals directed to the pathology, or directed to other symptoms of the pathology.

Chemistry of PAR-1 Antagonist

[0063] More particularly, the present invention is directed to compounds of the following formula (I):

[0064] wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, X, m, n, and p are as previously defined.

[0065] When a particular group is “substituted” (e.g., Phe, aryl, heteroalkyl, heteroaryl), that group may have one or more substituents, preferably from one to five substituents, more preferably from one to three substituents, most preferably from one to two substituents, independently selected from the list of substituents.

[0066] Under standard nomenclature used throughout this disclosure, the terminal portion of the designated side chain is described first, followed by the adjacent functionality toward the point of attachment. Thus, for example, a “phenylC₁-C₆ alkylamidoC₁-C₆alkyl” substituent refers to a group of the formula

[0067] The PAR-1 antagonist may also be present in the form of a pharmaceutically acceptable salt. The pharmaceutically acceptable salt generally takes a form in which the basic nitrogen is protonated with an inorganic or organic acid.

[0068] Representative organic or inorganic acids include hydrochloric, hydrobromic, hydriodic, perchloric, sulfuric, nitric, phosphoric, acetic, propionic, glycolic, lactic, succinic, maleic, fumaric, malic, tartaric, citric, benzoic, mandelic, methanesulfonic, hydroxyethanesulfonic, benzenesulfonic, oxalic, pamoic, 2-naphthalenesulfonic, p-toluenesulfonic, cyclohexanesulfamic, salicylic, saccharinic or trifluoroacetic.

[0069] Where the PAR-1 antagonist have at least one chiral center, they may accordingly exist as enantiomers. Where the compounds possess two or more chiral centers, they may additionally exist as diastereomers. It is to be understood that all such isomers and mixtures thereof are encompassed within the scope of the present invention. Furthermore, some of the crystalline forms for the compounds may exist as polymorphs and as such are intended to be included in the present invention. In addition, some of the compounds may form solvates with water (i.e., hydrates) or common organic solvents, and such solvates are also intended to be encompassed within the scope of this invention.

[0070] As used herein, unless otherwise noted alkyl and alkoxy whether used alone or as part of a substituent group, include straight and branched chains having 1 to 8 carbon atoms, or any number within this range. For example, alkyl radicals include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, 3-(2-methyl)butyl, 2-pentyl, 2-methylbutyl, neopentyl, n-hexyl, 2-hexyl and 2-methylpentyl. Alkoxy radicals are oxygen ethers formed from the previously described straight or branched chain alkyl groups. Cycloalkyl groups contain 3 to 8 ring carbons and preferably 5 to 7 carbons. Similarly, alkenyl and alkynyl groups include straight and branched chain alkenes and alkynes having 1 to 8 carbon atoms or any number within this range.

[0071] The term “aryl” as used herein refers to an unsubstituted or substituted aromatic group such as phenyl and naphthyl.

[0072] The term “heteroalkyl” as used herein represents an unsubstituted or substituted stable three to seven membered monocyclic saturated ring system which consists of carbon atoms and from one to three heteroatoms selected from N, O or S, and wherein the nitrogen or sulfur heteroatoms may optionally be oxidized, and the nitrogen heteroatom may optionally be quaternized. The heteroalkyl group may be attached at any heteroatom or carbon atom which results in the creation of a stable structure. Examples of such heteroalkyl groups include, but are not limited to azetidinyl, piperidinyl, pyrrolidinyl, piperazinyl, oxopiperazinyl, oxopiperidinyl, oxoazepinyl, azepinyl, tetrahydrofuranyl, dioxolanyl, tetrahydroimidazolyl, tetrahydrothiazolyl, tetrahydrooxazolyl, tetrahydropyranyl, morpholinyl, thiomorpholinyl, thiamorpholinyl sulfoxide, thiamorpholinyl sulfone and oxadiazolyl.

[0073] Preferred heteroalkyl groups include pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, azetidinyl and tetrahydrothiazolyl.

[0074] The term “heteroaryl” as used herein represents an unsubstituted or substituted stable five or six membered monocyclic aromatic ring system or an unsubstituted or substituted nine or ten membered benzo-fused heteroaromatic ring system or bicyclic heteroaromatic ring system which consists of carbon atoms and from one to four heteroatoms selected from N, O or S, and wherein the nitrogen or sulfur heteroatoms may optionally be oxidized, and the nitrogen heteroatom may optionally be quaternized. The heteroaryl group may be attached at any heteroatom or carbon atom that results in the creation of a stable structure. Examples of heteroaryl groups include, but are not limited to pyridyl, pyridazinyl, thienyl, furanyl, imidazolyl, isoxazolyl, oxazolyl, pyrazolyl, pyrrolyl, thiazolyl, thiadiazolyl, triazolyl, benzimidazolyl, benzofuranyl, benzothienyl, benzisoxazolyl, benzoxazolyl, benzopyrazolyl, indolyl, benzothiazolyl, benzothiadiazolyl, benzotriazolyl adeninyl or quinolinyl. Prefered heteroaryl groups include pyridyl, pyrrolyl, pyrazinyl, thiadiazolyl, pyrazolyl, thienyl, triazolyl and quinolinyl.

[0075] The term “aralkyl” means an alkyl group substituted with one, two or three aryl groups (e.g., benzyl, phenylethyl, diphenylmethyl, triphenylmethyl). Similarly, the term “aralkoxy” indicates an alkoxy group substituted with an aryl group (e.g., benzyloxy). The term aminoalkyl refers to an alkyl group substituted with an amino group (i.e., -alkyl-NH₂). The term “alkylamino” refers to an amino group substituted with an alkyl group (i.e., -NH-alkyl). The term “dialkylamino” refers to an amino group which is disubstituted with alkyl groups wherein the alkyl groups can be the same or different (i.e., -N-[alkyl]₂).

[0076] The term “acyl” as used herein means an organic radical having 1 to 6 carbon atoms (branched or straight chain) derived from an organic acid by removal of the hydroxyl group.

[0077] The term “oxo” refers to the group ═O.

[0078] The term “carbonyl” refers to the group C(O).

[0079] The term “halogen” shall include iodine, bromine, chlorine and fluorine.

[0080] Whenever the term “alkyl” or “aryl” or either of their prefix roots appear in a name of a substituent (e.g., aralkyl, dialkylamino) it shall be interpreted as including those limitations given above for “alkyl” and “aryl.” Designated numbers of carbon atoms (e.g., C₁-C₆) shall refer independently to the number of carbon atoms in an alkyl or cycloalkyl moiety or to the alkyl portion of a larger substituent in which alkyl appears as its prefix root.

[0081] It is intended that the definition of any substituent or variable at a particular location in a molecule be independent of its definitions elsewhere in that molecule. It is understood that substituents and substitution patterns on the compounds of this invention can be selected by one of ordinary skill in the art to provide compounds that are chemically stable and that can be readily synthesized by techniques known in the art as well as those methods set forth herein.

[0082] As used herein, the term “composition” is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combinations of the specified ingredients in the specified amounts. Accordingly, pharmaceutical compositions containing the compounds of the present invention as the active ingredient as well as methods of preparing the instant compounds are also part of the present invention.

[0083] Particularly preferred representative compounds of the present invention and their biological data are shown in Table 1 and Table 2, following. Table 1 and Table 2 each contain IC₅₀ values (μM) against platelet aggregation stimulated by thrombin and IC₅₀ values (μM) of the compounds in a thrombin receptor binding assay. The assays used to determine the biological data for the instant compounds are further described herein. TABLE 1 Thrombin Receptor Antagonists

GFP Recptr Aggr.* Bdg.** Cmpd R₆ X R₇ m IC₅₀, μM IC₅₀, μM 1 (CH₂)₂NH₂ N H 1 1.3 0.5 2 (CH₂)₂NH₂ CH H 1 1.7 0.3 3 (CH₂)₄NH₂ N H 1 0.26 0.3 4 (CH₂)₄NH₂ CH H 1 0.26 0.22 5 PhCH₂ CH H 1 22 0.38 6 2-ThienylCH₂ CH (CH₂)₂NH₂ 0 0.6 10.3 7 c-C₆H₁₁CH₂ CH (CH₂)₂NH₂ 0 1.0 8.8 8 4-PyridylCH₂ CH (CH₂)₂NH₂ 0 0.40 29 9 H N (CH₂)₂NH₂ 0 0.26 0.10 10 4-PyridylCH₂ CH (CH₂)₃NH₂ 0 0.51 0.10 11 H CH (CH₂)₃NH₂ 0 1.7 0.10 12 H CH CH₂NH₂ 0 0.99 0.07

[0084] TABLE 2 Thrombin Receptor Antagonists

GFP Aggr.* Recptr Bdg.** Cmpd R₄ IC₅₀, μM IC₅₀, μM 13 (CH₂)₅NH₂ 1.0 >100 14 4-ClPhCH₂ 6.3 6.9 15 4-FPhCH₂ 2.1 8.1

[0085] The antagonists of the present invention may be prepared via either solution-phase or solid-phase methods. In general, the compounds may be synthesized in solution following Generic Scheme A or Generic Scheme B.

[0086] As shown in Generic Scheme A, the 6-nitroindole A1 may be alkylated with the appropriate halide and a base such as potassium or cesium carbonate in a dipolar aprotic solvent such as DMF or THF. Upon work-up, the crude intermediate may be reduced with a reducing agent such as iron and acetic acid or dimethyl hydrazine to give the amine A2. The Fmoc protected amino-acid A3, which may be commercially available or prepared by alkylation of R₆NH₂ with a 2-bromo acetic acid followed by Fmoc protection, is coupled to an R₈ substituted amine using classical coupling agents such as DCC or DIC with HOBT in a dipolar aprotic solvent such as ACN or DMF. The Fmoc group is removed with a secondary amine such as diethylamine in a dipolar aprotic solvent such as ACN or DMF. The resultant amine may then be coupled with bromoacetic acid in DCC and the intermediate bromide alkylated with a R₄ substituted amine in the presence of triethylamine to afford the amine A4. Alternatively, the amine may be coupled with another Fmoc protected amino-acid followed by Fmoc deprotection to afford the amine A4. The amine A2 is reacted with a phosgene equivalent such as 4-nitrophenyl chloroformate, phosgene or “COCl₂,” phenyl chloroformate, triphosgene or “(CCl₃O)₂CO,” carbonyldiimidazole, diethyl carbonate or diphenyl carbonate and DIEA, then combined with A4 to give the urea A5. The urea A5 is then added to a preformed Mannich intermediate from reaction of an amine with formaldehyde in acetic acid to afford (after TFA deprotection of side-chains if necessary) the target A6.

[0087] As shown in Generic Scheme B, the indole A1 is converted to indazole B1 with sodium nitrite and HCl and then reductively aminated with an amine and a reducing agent such as sodium triacetoxyborohydride to give B2. B2 was then alkylated with an appropriate alkyl halide and a base such as potassium hydroxide in a dipolar aprotic solvent such as DMF, followed by reduction of the nitro group using classical reducing agents such as tin chloride and HCl to give the amine B3. The amine B3 was reacted with a phosgene equivalent and DIEA then combined with amine A4, as prepared above, to give the desired urea; again, deprotection of side-chain protecting groups with an acid such as TFA may be required to afford the indazole targets B4.

[0088] The side-chain amine in antagonists such as Compound 1 and Compound 6 may be converted to other fuinctional groups such as acetamnidine and guanidine by using standard procedures. For example, the acetamidine and guanidine groups can be introduced by treating the side-chain amine with S-2-naphthylmethyl thioacetimidate hydrobromide and 2-methyl-2-thiopseudourea, respectively.

[0089] Extending the carbon chain from p being 1 to n being 2 at the 3-position of the indole [see general formula (I), X=CH] may be achieved by treating the dimethylamino Mannich base (when p is 1, R₁ is NMe₂) with KCN followed by reducing the cyano group to an amine.

[0090] Extending the carbon chain from p being 1 to n being 2 at the 3-position of the indazole [see general formula (I), X=N] may be introduced in the intermediate B1 (Generic Scheme B) via aldehyde-nitromethane condensation followed by reduction of the resulting α,β-unsaturated nitro compounds to saturated amine.

[0091] Where the processes for the preparation of the compounds according to the invention give rise to mixture of stereoisomers, these isomers may be separated by conventional techniques such as preparative chromatography. The compounds may be prepared in racemic form, or individual enantiomers may be prepared either by enantiospecific synthesis or by resolution. The compounds may, for example, be resolved into their components enantiomers by standard techniques, such as the formation of diastereomeric pairs by salt formation with an optically active acid, such as (−)-di-p-toluoyl-d-tartaric acid and/or (+)-di-p-toluoyl-l-tartaric acid followed by fractional crystallization and regeneration of the free base. The compounds may also be resolved by formation of diastereomeric esters or amides, followed by chromatographic separation and removal of the chiral auxiliary. Alternatively, the compounds may be resolved using a chiral HPLC column.

[0092] During any of the processes for preparation of the compounds of the present invention, it may be necessary and/or desirable to protect sensitive or reactive groups on any of the molecules concerned. This may be achieved by means of conventional protecting groups, such as those described in Protective Groups in Organic Chemistry, ed. J.F.W. McOmie, Plenum Press, 1973; and T.W. Greene & P.G.M. Wuts, Protective Groups in Organic Synthesis, John Wiley & Sons, 1991. The protecting groups may be removed at a convenient subsequent stage using methods known from the art.

[0093] To prepare the pharmaceutical compositions of this invention, one or more compounds of formula (I) or salt thereof of the invention as the active ingredient, is intimately admixed with a pharmaceutical carrier according to conventional pharmaceutical compounding techniques, which carrier may take a wide variety of forms depending on the form of preparation desired for administration, e.g., oral or parenteral such as intramuscular. In preparing the compositions in oral dosage form, any of the usual pharmaceutical media may be employed. Thus, for liquid oral preparations, such as, for example, suspensions, elixirs and solutions, suitable carriers and additives include water, glycols, oils, alcohols, flavoring agents, preservatives, coloring agents and the like; for solid oral preparations such as, for example, powders, capsules, caplets, gelcaps and tablets, suitable carriers and additives include starches, sugars, diluents, granulating agents, lubricants, binders, disintegrating agents and the like. Because of their ease in administration, tablets and capsules represent the most advantageous oral dosage unit form, in which case solid pharmaceutical carriers are obviously employed. If desired, tablets may be sugar coated or enteric coated by standard techniques. For parenterals, the carrier will usually comprise sterile water, though other ingredients, for example, for purposes such as aiding solubility or for preservation, may be included. Injectable suspensions may also be prepared, in which case appropriate liquid carriers, suspending agents and the like may be employed. The pharmaceutical compositions herein will contain, per dosage unit, e.g., tablet, capsule, powder, injection, teaspoonful and the like, an amount of the active ingredient necessary to deliver an effective dose as described above. The pharmaceutical compositions herein will contain, per unit dosage unit, e.g., tablet, capsule, powder, injection, suppository, teaspoonful and the like, from about 0.03 mg/kg to about 100 mg/kg (preferred from about 0.1 mg/kg to about 30 mg/kg) of a compound of the present invention and may be given at a dosage from about 0.1 mg/kg/day to about 300 mg/kg/day (preferred from about 1 mg/kg/day to about 50 mg/kg/day). The dosages, however, may be varied depending upon the requirement of the patients, the severity of the condition being treated and the compound being employed. The use of either daily administration or post-periodic dosing may be employed.

Example 1

[0094] Protease-activated receptors (PARs) belong to a family of G-coupled seven transmembrane receptors that are activated by a proteolytic cleavage of their N-termini. Recent studies suggest the involvement of protease-activated receptors-1 and -2 (PAR-1, PAR-2) activators in mast cell degranulation in various physiological and pathophysiological processes in inflammatory responses.

[0095] Although PAR-1 and PAR-2 activating proteases, thrombin and tryptase, have been associated with mast cell activation, PAR-1 and PAR-2 have not been localized within these cells. We describe here the localization of PAR-1 and PAR-2 in all mast cells from various normal human tissues using immunohistochemical and double immunofluorescence techniques. The presence of these receptors on the membrane may explain the actions of accessible extracellular thrombin and tryptase for mast cell activation. In addition to the membrane labeling, these receptors are also localized on the membrane of the intracellular tryptase-positive granules, which may function to sustain further mast cell degranulation upon exocytosis. The localization of these two receptors in mast cells suggests a novel mechanism for controlling mast cell activation through regulation of PAR-1 and PAR-2.

MATERIALS AND METHODS

[0096] Human checkerboard tissue blocks (Biomeda, Foster City, Calif.) were routinely processed for immunohistochemistry (D'Andrea et al. 1998a) and for double immunofluorescence (D'Andrea 1998b). Primary antibodies include monoclonal anti-human mast cell tryptase (1:500, Dako, Carpenturia, Calif.), polyclonal anti-human PAR-1 (1 μg/ml) raised against the C-terminus of the receptor (Smith-Swintosky et al. 1997), and polyclonal anti-human PAR-2C (1 g/ml) raised against a sequence spanning the cleavage domain (D'Andrea et al, 1998a). Briefly, slides were incubated (30 min at room temperature) with primary antibodies, followed by incubation with specific biotin conjugated secondary antibodies (Vector Labs, Burlingham, Calif.) which were then detected using the ABC-horseradish peroxidase system (Vector Labs). Slides were treated with 3′-diaminobenzidine (Biomeda, Foster City, Calif.) as the chromogen, stained in Mayer's hematoxylin and coverslipped with Permount (Fisher, Pittsburgh, Pa.).

[0097] For the double immunofluorescence (D'Andrea 1998b), the first primary antibody was incubated on the tissues and followed by FITC-conjugated secondary antibody (1:200, Vector Labs, Burlingham, Calif.). Subsequently, the second primary antibody was incubated on the tissues and followed by Texas Red-conjugated secondary antibody (1:50, Vector Labs, Burlingham, Calif.). Slides were coverslipped with anti-fade media containing the nuclear DAPI stain (Vector Labs, Burlingham, Calif.). Co-localization of the FITC and Texas Red signals were visualized as yellow fluorescence. A negative control for each antibody included the same species isotype nonimmune serum.

Results

[0098] Single immunohistochemical techniques were used to identify human mast cells in various normal human tissues using an antibody to mast cell tryptase (MCT). Mast cells were localized in a lymph node and in the submucosa of the large intestine. Extracellular labeling of MCT in the immediate pericellular vicinity was interpreted as an indication of mast cell degranulation (Buckley et al. 1998, Johnson et al. 1998), which was observed using mast cell tryptase immunolabeling. Localization of MCT was indicated by the presence of brown precipitate within the intracellular mast cell granules, whereas cells negative for MCT had blue nuclei only. Immunolocalization of MCT on the cell surface of degranulated mast cell located in the submucosa of the large intestine was observed. Antibodies specific to PAR-1 and PAR-2 were used to localize their respective antigens in the same normal human tissues. PAR-1 and PAR-2 were localized to the plasma membrane and the intracellular granule membranes of the mast cells localized in sections of the lymph node and the submucosa of the large intestine.

[0099] To determine the co-localization patterns of MCT and PAR-1 and PAR-2 in mast cells, we performed double immunofluorescence techniques on similar human tissues. Co-localization of a MCT Texas Red-positive signal with a PAR-1 or PAR-2 FITC-positive signal were interpreted as distinct yellow fluorescence. The co-localization of PAR-1 and MCT in mast cells was demonstrated in a lymph node. A similar approach was employed to demonstrate the co-expression of MCT and PAR-2 in a normal human uterus. We were not able to resolve the PAR-1 or PAR-2 plasma membrane signals due to the significant fluorescence obtained from the intracellular granules, which appeared to mask lower antigen signals within close proximity. Similarly, the co-expression of PAR-1 and PAR-2 was performed on similar tissues such as a lymph node.

[0100] Mast cells with positive MCT, PAR-1 and PAR-2 immunolabeling, were localized in the following tissues (sample size): large intestine (3), lung (5), pancreas (5), prostate (5), skin (3), small intestine (1), spleen (5), stomach (1), testis (2), tonsil (3), and uterus (3). A series of negative controls employed for the double immunofluorescence techniques included 1) replacement of the first primary antibody with similar isotype nonimmune serum; 2) replacement of the second primary antibody with similar isotype nonimmune serum; 3) replacement of both primary antibodies with negative control antibodies. All of these negative control antibodies did not yield detectable labeling.

Discussion

[0101] We describe here the presence of PAR-1 and PAR-2 on mast cells in various normal human tissues using immunohistochemical and double immunofluorescence techniques. More specifically, PAR-1 and PAR-2 are distributed on the plasma membrane and on the membranes of the intracellular tryptase-positive granules of the mast cells.

[0102] Mast cells are involved in numerous normal and pathophysiological conditions. Upon activation, they secrete a range of soluble mediators including histamine, heparin, leukotrienes, cytokines, growth factors and neutral proteases (Fawcett 1955, Galli et al. 1989, Gordon 1990, Bradding et al. 1995, Irani 1995, He and Walls 1997, Buckley et al. 1998, Johnson et al. 1998, Laine et al. 1999). Thus, mast cells represent an efficient system through which powerful mediating factors and enzymes are deposited locally upon activation. Current proposed mechanisms of mast cell activation include most notably the binding of an allergen to an IgE receptor on the mast cell membrane. Subsequent binding leads to degranulation and ensuing release of the mediators of immediate hypersensitivity from their storage sites in mast cell granules (Dvarak 1985, Galli et al. 1989, Gordon et al. 1990, Irani 1995, Johnson et al. 1998). In addition to the IgE pathway, mast cells may also be activated by a “histamine releasing factor” secreted from immunocompetent cells such as T lymphocytes (Segwick et al. 1981) and macrophages (Liu et al. 1986). Thrombin, which activates PAR-1 (Vu et al. 1991), has been reported to induce mast cell activation (Razin and Marx 1984, Cirino et al. 1996). Also, tryptase, a reported PAR-2 activator (Fox et al. 1997, Molino et al. 1997a) and a key secretory component of all human mast cells regardless of anatomical site (Craig et al. 1989, Irani 1995), can activate mast cells in vivo (He and Walls 1997). Other studies suggest that mast cell tryptase and SLIGRL, a PAR-2 activating peptide, (Kawabata et al. 1998) elicits PAR-2 mediated inflammation. These observations suggest the presence of mast cell receptors for thrombin and tryptase that initiate or potentiate mast cell activation. Our discovery of PAR-1 and PAR-2 on the plasma membrane of mast cells suggest a mechanism by which thrombin via PAR-1 (Razin and Marx 1984, Cirino et al. 1996) and tryptase via PAR-2 (Molino et al. 1997a, Fox et al. 1997, Kawabata et al. 1998) might mediate these processes.

[0103] These receptors can then be translocated with the granules to fuse to the mast cell surface through the process of exocytosis (Lawson et al. 1978, Ishizaka 1984, Dvorak et al. 1985, Burgess and Kelly 1987). Subsequently, PAR-1 and PAR-2 activation will transduce intracellular Ca²⁺ mobilization (Blackhart et al. 1996, Magazine et al. 1996), which is necessary for mast cell degranulation (Lawson et al. 1978). Therefore, it is possible that the function of PAR-1 and PAR-2 on the membranes of intracellular granules may be to sustain further mast cell degranulation by replenishing internalized PAR-1 and PAR-2 from the plasma membrane upon activation (Molino et al. 1997b).

[0104] We have localized PAR-1 and PAR-2 on mast cell plasma membrane and the membranes of the intracellular tryptase-positive granules through immunohistochemistry. The presence of PAR-1 and PAR-2 may explain the actions of PAR-1 and PAR-2 activators to stimulate mast cell degranulation. In addition, PAR-1 and PAR-2 may also function to sustain mast cell activation in a paracrine or autocrine fashion. In vivo and in vitro functional studies are necessary to elucidate the roles of PAR-1 and PAR-2 in mast cell activation in normal and pathological conditions. Thus, the discovery of two additional mast cell receptors suggests novel mechanisms to control mast cell activation through the regulation of PAR-1 and PAR-2. Ultimately, specific antagonists of PAR-1 and PAR-2 could be used as tools to probe this hypothesis. In addition, these antagonists might prove to be effective therapeutic agents for inflammatory driven conditions.

Example 2

[0105] The serine proteases, thrombin and trypsin, are among many factors that malignant cells secrete into the extracellular space to mediate metastatic processes such as cellular invasion, extracellular matrix degradation, angiogenesis and tissue remodeling. The degree protease secretion has been correlated to their metastatic potential. Protease activated receptors (PAR)-1 and -2, which are activated by thrombin and trypsin respectively, have not been extensively characterized in human tumors in situ. We investigated the presence of PAR-1 and -2 in human normal, benign and malignant tissues using immunohistochemistry and in situ hybridization. Our results demonstrated PAR-1 and -2 expression in the hosting stromal fibroblasts, mast cells, macrophages, endothelial cells and vascular smooth muscle cells of the metastatic tumor micro environment. Interestingly, the up-regulation of PAR-1 and -2 in reactive stromal fibroblasts surrounding the carcinoma cells was not observed in normal or benign conditions. Furthermore, in vitro studies using proliferating, smooth muscle actin (SMA) positive, human dermal fibroblasts demonstrated the presence of functional PAR-1 and -2 not detected in quiescent, SMA negative cultures. PAR-1 and -2 in the cells forming the tumor micro environment suggest that these receptors mediate the signaling of secreted thrombin and trypsin in the processes of cellular metastasis.

[0106] Reagents. Primary antibodies used in these experiments include the following:

[0107] desmin (Dako, Calif.), endothelial cell (CD31) (Dako, Calif.), fibroblast (prolyl 4-hydroxylase) (Dako, Calif.), macrophage (CD68) (Dako, Calif.), mast cell tryptase (Dako, Calif.), non-immuno serum (Vector Labs, Calif.), PAR-1 (RWJPRI, PA) (Smith-Swintosky et al. 1997; Cheung et al. 1999; Festoff et al. 2000), PAR-2 (RWJPRI, PA) (D'Andrea et al. 1998; Smith-Swintosky et al. 1997; Damiano et al. 1999), smooth muscle actin (Dako, Calif.), DNA topoisomerase IIα (Pharmingen, Calif.) (D'Andrea et al. 1994) and vimentin (Dako, Calif.).

[0108] 3′-biotinylated molecular probes used for in situ hybridization include the following: PAR-1 (5′ TTC ATT TTT CTC CTC CTC CTC CTC ATC C) (Research Genetics, AL) (Cheung et al. 1999; Festoff et al. 2000), PAR-2 (5′ CAA TAA TGT AGA CGA CCG GAA GAA AGA) (Research Genetics, AL) (Daminano et al. 1999), glyceraldehyde-3-phosphate dehydrogenase (GAP-DH) (5′ GAC GCC TGC TTC TCC TCC TTC TTG) (Ransom Hill, Calif.), poly d(T) (5′ TTT TTT TTT TTT TTT TTT TTT TTT) (Research Genetics, Calif.), lac Z (5′ CAC AGC GGA TGG TTC GGA TAA TG) (Ransom Hill, Calif.).

[0109] Immunohistochemistry. Commercial human checkerboard tissue slides (Dako, Carpenteria, Calif.; Biomeda, Foster City, Calif.) representing normal breast tissues (n=26), benign breast fibroadenomas (n=14), malignant breast carcinomas (n=46) and six other non-breast human carcinomas (n=4-6) were deparaffinized, hydrated and processed for routine immunohistochemistry (IHC) as previously described (D'Andrea et al., 1998). Briefly, slides were microwaved in Target buffer (Dako), cooled, placed in phosphate-buffered saline (pH 7.4, PBS) and treated with 3.0% H₂O₂ for 10 min. Slides were processed through an avidin-biotin blocking system according to the manufacturer's instructions (Vector Labs, Burlingame, Calif.) and then placed in PBS. All subsequent reagent incubations and washes were performed at room temperature. Normal blocking serum (Vector Labs) was placed on all slides for 10 min. After briefly rinsing in PBS, primary antibodies were placed on slides for 30 min. PAR-1 (Smith-Swintosky et al., 1997; Cheung et al., 1999; Festoffet al., 2000) and PAR-2 (Smith-Swintosky et al., 1997; D'Andrea et al., 1998;

[0110] Damiano et al., 1999) antibodies had been previously characterized. The slides were washed and biotinylated secondary antibodies, goat anti-rabbit (polyclonal antibodies) or horse anti-mouse (monoclonal antibodies) were placed on the tissue sections for 30 min (Vector Labs). After rinsing in PBS, the avidin-horseradish peroxidase-biotin complex reagent (ABC, Vector Labs) was added for 30 min. Slides were washed and treated with the chromogen 3,3′-diaminobenzidine (DAB, Biomeda) twice for five min each, then rinsed in dH₂0, and counterstained with hematoxylin. A monoclonal antibody to vimentin, the widely conserved ubiquitious intracellular filament protein, were utilized as a positive control to demonstrate tissue antigenicity and control reagent quality. The negative control included replacement of the primary antibody with pre-immune serum or with the same species IgG isotype non-immune serum.

[0111] Analysis of PAR-1 and PAR-2 Immunoreactivity. The tissues were scored for the intensity of PAR-1 and PAR-2 immunoreactivity to compare the relative amounts of PAR-1 and PAR-2 in the stromal fibroblasts and epithelial cells in the normal (n=26), benign (n=14) and malignant (n=46) breast tissues. For each tissue, epithelial cells (n=25) and fibroblasts (n=15-25) the presence of PAR-1 and PAR-2 immunoreactivity in the stromal fibroblasts were scored under a 20x objective according to the following criteria: 1) no immunoreactivity IR (0.0); 2) weak, light brown immunoreactivity IR (1.0); 3) moderate brown immunolabeling IR (2.0), and 4) intense, dark brown immunoreactivity IR (3.0) (Table 1). The negative controls did not produce observable labeling IR (0.0). The data from each tissue was averaged and then grouped according to normal, benign and malignant tissues for PAR-1 and PAR-2 expression.

[0112] Double Immunohistochemistry. In an effort to determine if there was a correlation between the up-regulation of PAR-1 and -2 with cell proliferation, we used double immunohistochemical methods (IHC:IHC) to detect PAR-1 or -2 expression simultaneously with detection of a proliferation marker, DNA topoisomerase IIα (Topo IIα) (D'Andrea et al., 1994). Protocols for IHC:IHC have been previously described (D'Andrea et al., 1999). Briefly, slides were first processed for single IHC labeling protocols for detection of PAR-1 or PAR-2 as described above. Without processing the slides for hematoxylin, Topo IIα antibodies (Pharminigen, San Diego, Calif.) were placed on the tissues for 30 min. After brief PBS washes, the biotinylated horse anti-mouse secondary antibodies (Vector Labs) were similarly incubated. The presence of Topo IIα positive cells were visualized using an alkaline phosphatase detection system through incubation with alkaline phosphatase conjugated ABC (Vector Labs) followed by development using the Fast Red chromogen (Sigma). Slides were then routinely counterstained and mounted.

[0113] In Situ Hybridization. Slides were routinely dewaxed, rehydrated, placed in 3% H₂O₂ for 10 min at room temperature and processed for in situ hybridization (ISH) as previously described (Cheung et al., 1999; Damiano et al., 1999; Festoff et al., 2000). Briefly, after a 5 min wash in water, slides were placed in Universal Buffer (Research Genetics, Huntsville, AL) and the tissue sections were digested with pre-diluted pepsin (Research Genetics) for 10 min at 42° C. Sections were washed and then dehydrated in 100% alcohol for 1 min. Each probe was diluted to 1.0 μg/ml in commercially formulated hybridization buffer (Biomeda) and heated for 5 min at 103° C. in a microcentrifuge tube on a heat block. Anti-sense, biotinylated oligonucleotide probes to PAR-1 (Cheung et al., 1999; Festoff et al., 2000) and PAR-2 (Damiano et al., 1999) mRNAs have been previously characterized. The ISH probes were maintained at 42° C. in a water bath until placement onto the tissue sections. Ten microliters of probe was added to each section and a coverslip was gently placed to cover the solution and prevent evaporation. Slides were placed into a humid chamber and incubated at 42° C. for 2 h. After hybridization, they were then immediately placed into a low stringency wash (2xSSC) for 5 min at 42° C., followed by a high stringency wash (0.1xSSC) for 5 min at 42° C. Sections were washed in PBS and treated with ABC (Vector Labs) for 1 h at room temperature. After washing, sections were placed in DAB (Biomeda) for 2 times 5 min, washed, briefly stained with hematoxylin, dehydrated in graded ethanols, cleared in xylene, coverslipped in Permount (Fisher Scientific, Pittsburgh, Pa.) and photographed with an Olympus BX50 light microscope. Positive controls included two biotinylated mRNA oligonucleotide probes: GAPDH mRNA and a poly d(T) probe that hybridizes non-specifically to all mRNA. Negative controls included 1) the absence of probe in the probe cocktail; 2) a biotinylated probe that hybridizes to lac Z operon MRNA (Table 2); and 3) pre-digestion of the tissues with RNase, DNase free (10 μg/μl, Boehinger Mannheim, City, State) for 2 hours at 42° C. before probe hybridization.

[0114] Cell Culture. Human neonatal dermal fibroblasts and their culture media were obtained from Clonetics/BioWhittaker (Walkersville, Md.). Cells were incubated for either 2 days (proliferating) or 9 days (quiescent) prior to evaluation without serum exchange. Cell suspensions (5×10⁴/ml) were plated in 96-well microtiter plates for calcium mobilization studies and were seeded in 4-welled chamber slides (NUNC, Naperville, III) for immunocytochemistry. In an effort to mimic the in vivo activation of differentiated, quiescent fibroblasts in vitro, the 9-day, quiescent cells were subjected to random scrape wounding induced by the end of a pipette and cultured for 5 additional days without medium exchange. As a control, other 9-day cultures without scrapes continued to grow similarly.

[0115] Immunocytochemistry. Four-chambered culture slides were routinely fixed with 10% neutral buffered-saline for 10 min at room temperature, rinsed in PBS and then assayed for immunocytochemistry as previously described (Chen et al., 1998; Smith-Swintosky et al., 1998). Hyper-confluent (quiescent) sub-confluent proliferating) and wounded cultured slides were processed for immunocytochemistry using antibodies to PAR-1, PAR-2, SMA, Topo IIα and pre-immune serum. All buffered steps were performed using Automation Buffer (Research Genetics) with Tween-20. Primary antibodies were added to the wells for 30 min at room temp. After washes, the secondary antibodies were similarly incubated on the cells. Subsequently, the presence of the primary antibodies were detected using the ABC (Vector Labs) followed by DAB development for 2 times 5 min each. Chambers were removed and then were counterstained using hematoxylin then coverslipped.

Results

[0116] In situ PAR-1 and PAR-2 Protein Expression. PAR-1 and PAR-2 proteins were localized in formalin-fixed, paraffin embedded tissues. Normal (n=26), benign (n=14) and malignant (n=46) human breast tissues and six non-breast carcinomas (n-4-6 of each) were assayed simultaneously in a multi-tissue format to eliminate potential staining artifacts such as slide-to-slide and run-to-run variability. The relative amounts of PAR-1 and PAR-2 immunoreactivity in the epithelial cells and the surrounding sromal fibroblasts in the normal benign and malignant breast tissues are presented in FIG. 1. Marginal increases of PAR-1 and PAR-2 expression were observed in the malignant cells as compared to the normal and benign epithelial cells. Striking changes in PAR-1 and PAR-2 expression were noted in the stromal fibroblasts surrounding the malignant cells as compared to the fibroblasts surrounding the normal and benign epithelial cells. No PAR-1 or PAR-2 immunolabeling was observed in the stromal fibroblasts of the benign (n=14) or normal (n=26) breast tissues. In contrast, most malignant tissues had prominent moderate to strong PAR-1 (n=39/46) and PAR-2 (n-37/46) labeling in the stromal fibroblasts.

[0117] We applied additional immunohistochemical markers to further characterize these tissues (FIG. 1). No immunolabeling was detected using negative control antibodies in normal FIG. 2A), benign (FIG. 2B) and malignant (FIG. 2C) breast tissue. Smooth muscle actin (SMA)-positive immunolabeling was localized in the myoepithelial cells (large arrowheads) around the epithelial ducts and in the vascular smooth muscle cells in the normal (FIG. 2D) and benign fibroadenoma (FIG. 2E) breast tissues. SMA immunolabeling was absent from stromal fibroblasts in the normal (FIG. 2D) and benign (FIG. 2E) tissues, which were immunoreactive to the fibroblast marker (data not presented). In the malignant breast carcinoma tissues, SMA immunolabeling (small arrowheads) was prominent in the stromal fibroblasts surrounding the tumor cells, in addition to the vascular smooth muscle cells (FIG. 2F). Carcinoma cells (large arrowheads) did not express SMA. Positive, nuclear Topo IIα immunolabeling (large arrowhead), a marker for proliferating cells (D'Andrea and Cheung, 1994), was sparsely observed in normal breast epithelial cells (FIG. 2G) and absent in stromal fibroblasts (small arrowheads). Topo IIα nuclear immunolabeling was observed in the benign, fibroadenoma cells (large arrowheads), but was similarly absent in the surrounding stromal fibroblasts (small arrowheads) in FIG. 2H. In contrast, Topo IIα nuclear immunolabeling was observed in stromal fibroblasts (small arrowheads) and tumor cells (large arrowheads) of the malignant tissues (FIG. 2I). Furthermore, the stromal fibroblasts surrounding the malignant cells also expressed vimentin but did not express desmin (data not presented).

[0118] Immunolocalization studies indicated that PAR-1 and PAR-2 were co-expressed in the different cell types in normal, benign and malignant tissues. In normal breast tissues, immunolabeling (large arrowheads) was confined to the normal breast ductal epithelial cells and myoepethelial cells (FIGS. 2J and 2M). Immunolabeling (large arrowheads) was also observed in the fibroadenoma cells (FIGS. 2K and 2N). In both cases, normal and benign tissues, surrounding stromal fibroblasts (small arrowheads) did not express detectable PAR-1 or PAR-2. In the breast carcinoma tissues, PAR-1 and PAR-2 positive immunoreactivity was observed in many cell types forming the TME such as in the malignant cells (large arrowheads) and the stromal fibroblasts (small arrowheads) (FIGS. 2L and 2O). Although not present in these photomicrographs, PAR-1 and PAR-2 immunolabeling was also observed in endothelial cells, vascular smooth muscle cells as well as in the mast cells and macrophages. The PAR-1 and PAR-2 mast cell labeling pattern was consistent with our previous report (D'Andrea et al., 2000) and was similarly localized to the plasma membrane and to the membranes of the secretory vesicles. PAR-1 and PAR-2 positive macrophages were also observed around these cancerous tissues. Labeling in the macrophages was observed in or on the plasma membrane as well as intracellularly. The identity of the mast cells and macrophages were confirmed in these tissue sections using antibodies to mast cell tryptase (MCT) and macrophages (CD68) (data not presented).

[0119] PAR-1 and PAR-2 Expression in other Tumors. Other human non-breast malignant tumors demonstrated similar PAR-1 and PAR-2 expression in the tumor cells (large arrowheads), stromal fibroblasts (small arrowheads), mast cells and macrophages (arrows), as well as in the endothelial and vascular smooth muscle cells (FIG. 3). FIG. 3 shows PAR-1 (FIGS. 3A, 3C and 3E) and PAR-2 (FIGS. 3B, 3D and 3F) immunolabeling in tissues representing a gastric carcinoma (n=4, FIGS. 3A and 3B), an undifferentiated carcinoma (n=-4, FIGS. 3C and 3D) and a lung adenocarcinoma (n=4, FIGS. 3E and 3F). PAR-1 and PAR-2 immunoreactivity was similarly present in heptacarcinomas (n=6), thyroid carcinomas (n=4) and ovarian carcinomas (n=6) (data not shown). Positive PAR-1 and PAR-2 immunoreactivity was also observed on surrounding endothelial and vascular smooth muscle cells, as well as in the stromal fibroblasts in contrast to the absence of PAR-1 and PAR-2 immunoreactivity in the stromal fibroblasts on the normal tissue counterparts (data not presented).

[0120] In situ PAR-1 and PAR-2 mRNA Expression. The PAR-1 and PAR-2 protein expression correlated well with their respective MRNA levels in the same tissues as determined by in situ hybridization. The localization patterns of PAR-1 (FIG. 4A) and PAR-2 (FIG. 4B) mRNA were observed in human breast carcinoma tissues (n=48). FIG. 4A shows the intracellular localization of PAR-1 mRNA in the malignant tumor cells (large arrowheads) and in the surrounding stromal fibroblasts (small arrowheads). PAR-1 mRNA was not present in the stromal cells of the normal (n=26) and benign (n=10) breast tissues (data not presented). Similar localization patterns were observed for PAR-2 in the same breast carcinoma tissues as shown in FIG. 4B, and PAR-2 mRNA was also not present in the stromal cells of the normal and benign breast tissues (data not presented). When the same tissues were probed with the lac Z biotinylated mRNA probe (negative control), no observable labeling was observed in tumor cells (large arrowheads) or stromal fibroblasts (small arrowheads) (FIG. 4C). As a positive control probe, cells also expressed GAPDH MnRNA (FIG. 4D).

[0121] In addition, PAR-1 and PAR-2 mRNA was similarly observed in the following tissues: gastric carcinomas (n=4), undifferentiated carcinomas (n=4), lung adenocarcinomas (n=4), heptacarcinomas (n=6), thyroid carcinomas (n=4) and ovarian carcinomas (n=6) (data not shown).

[0122] PAR-1 and PAR-2 Expression is Associated with Proliferating Cells. The results of double immunohistochemical labeling using antibodies to PAR-1 or PAR-2 with antibodies to Topo IIα, demonstated that all proliferating cells expressed PAR-1 and PAR-2 immunolabeling. FIG. 5 A and 5B show representative examples of these results. Co-localization (arrowheads of PAR-1 or PAR-2 with Topo IIα positive immunolabeling was observed in both malignant cells and stromal fibroblasts.

[0123] In Vitro PAR-1 and PAR-2 Expression. Our IHC and ISH results indicated that PAR-1 and PAR-2 expression was induced in stromal fibroblasts during the transition to a myofibroblast phenotype. We utilized ICC to determine if this transition could be mimicked in vitro. Hyper-confluent, fibroblast cultures (quiescent conditions) were compared to 1) sub-confluent cultures with visible mitotics (proliferative conditions), and 2) confluent cultures subjected to a mechanical scrape and allowed to recover for 5 days without changing the media (wound conditions). FIG. 6 (FIGS. 6A-6C) shows the lack of observable immunolabeling using negative control antibodies in all three tissue culture conditions. SMA immunolabeling was present in the proliferating cells (FIG. 6E, arrowheads) and in the cells migrating over the scraped area (FIG. 6F, arrowheads), but was absent in the confluent cultured cells (FIG. 6D) suggesting that the confluent conditions produced quiescent, differentiated cells, which were not myofibroblasts. Immunoreactivity to the proliferation marker, Topo IIα, was present in the nuclei of the proliferating cells in the sub-confluent cultures (FIG. 6H, arrowheads) and in the cells migrating over the scraped area in the wounded cultures (FIG. 6I, arrowheads) but was absent in the cell nuclei of the quiescent cells (FIG. 6G) further confirming the quiescent, non-proliferating status of these differentiated fibroblasts when grown to confluency.

[0124] Positive intracellular and membrane PAR-1 and PAR-2 immunoreactivity (arrowheads) was not observed in the quiescent, non-proliferating cells (FIGS. 6J and 6M, respectively). However, positive PAR-1 and PAR-2 immunolabeling (arrowheads) was observed in the proliferating cells in the sub-confluent (FIGS. 6K and 6N, respectively) and wounded (FIGS. 6L and 6O, respectively) conditions.

Discussion

[0125] One of the most important features in cell metastasis is the ability of tumor cells to produce extracellular conditions conducive to their growth through degradation and subsequent remodeling of the extracellular matrix. This study provides evidence for the presence of PAR-1 and PAR-2 not only on the malignant carcinoma cells, but also on the cell types forming the tumor micro environment (TME), including mast cells, vascular endothelial cells, smooth muscle cells, macrophages and most interestingly, on reactive stromal fibroblasts. By expressing PAR-1 and PAR-2, these cell types may act as proteolytic sensors to extracellular thrombin and typsin, initiating a cellular response to tissue damage incurred through the processes of cell metastasis. The remodeling of the tumor stroma provides a permissive environment for tumor metastasis, relying on the interplay of all the cells within the TME.

[0126] PAR-1 and PAR-2 expression has previously been shown on endothelial cells, vascular smooth muscle cells and mast cells. It is therefore not surprising to find similar results for these cell types within the TME. Activation of either PAR-1 or PAR-2 on these cells results in characteristic events associated with inflammatory responses such as generation of cytokines, expression of adhesion molecules and increased vascular permeability. However, little is known about the presence of PAR-1 and PAR-2 on macrophages. It has been reported that macrophages can secrete thrombin (Lindahl et al., 1989) and that thrombin has been localized in pulmonary alveolar macrophages (Zacharski et al., 1995), suggesting an association between macrophages and thrombin. The presence of PAR-1 and PAR-2 on human macrophages in malignant tumors in situ has not been reported previously, although PAR-2 immunoreactivity has been reported on macrophage-like cells in the adventitia of the mouse isolated ureter (Webber et al., 1999). Here, we show that macrophages express both PAR-1 and PAR-2. PAR-1 and PAR-2 activation may provide a stimulus for macrophages to proliferate, migrate and/or phagocytize degraded stromal proteins, in addition to synthesizing and secreting thrombin and growth factors into the TME.

[0127] The most striking observation from our study is the presence of PAR-1 and PAR-2 on the stromal fibroblasts surrounding the metastatic tumor cells but not on the stromal fibroblasts surrounding the benign, non-metastatic or normal epithelial cells. The exact origin of the PAR-1 and PAR-2 expressing stromal fibroblasts is unclear, i.e. local dedifferentiated stromal fibroblasts, vascular smooth muscle cells or migrating undifferentiated stem cells such as pericytes (Ronnov-Jessen et al., 1995). In breast cancer, it has been shown that primarily fibroblasts convert to the myofibroblast phenotype when exposed to tumor cells; vascular smooth muscle cells and pericytes can also differentiate to myofibroblasts, but to a lesser extent (Ronnov-Jessen et al., 1995). The stromal fibroblasts associated with metastatic tumors in our study were characterized by the positive expression of smooth muscle actin (SMA), prolyl 4-hydroxylase (a fibroblast marker), Topo IIα (a proliferation marker) and vimentin, as well as the absence of the vascular markers desmin and CD31, confirming the fibroblastic nature of these cells (Ronnov-Jessen et al., 1995), (Webber et al., 1999; Chiavegato et al., 1993; Sappino et al., 1990; Babij et al., 1993).

[0128] Reactive stromal myofibroblasts are frequently associated with cancers of epithelial origin, a process known as desmoplasia (Schmitt-Graff et al., 1994). The induction of this phenotype has not been well characterized, however in vitro studies have indicated that diffusible signals, such as TGF-β, generated from primed or initiated carcinoma cells are involved (Ronnov-Jessen et al., 1995; Olumi et al., 1999; Noel, 1998; Lieubeau et al., 1994). The stromal myofibroblasts, in turn, influence the invasive and metastatic potential of carcinoma cells by an unidentified mechanism¹ once the carcinoma cells invade the basement membrane surrounding the epithelial cells. Elaboration of matrix degrading proteases, deposition of new extracellular matrix proteins to facilitate tumor cell adhesion, cell motility and cell proliferation (Gregoire and Lieubeau, 1995; Chambers et al., 1998), and release of cytokines and growth factors by these myofibroblasts, emphasizes the importance of this phenotypic change to the invasiveness of the tumor. PAR-1 and PAR-2 activation results in many of these biochemical events indicating that they are likely participants in the balance of tumor containment and/or metastasis (Hung et al., 1992; Vouret-Craviari et al, 1992; Dawes et al., 1993; Grubber et al., 1997; Akers et al., 2000; Vrana et al., 1996). Moreover, the expression of tissue factor, an essential co-factor for plasma coagulation factor VII/VIIa, was reported to be consistently observed in stromal cells of invasive breast carcinomas but not in the benign breast tumors (Vrana et al., 1996). The increased presence of tissue factor/factor VIIa within the TME, which in turn can generate thrombin via the extrinsic coagulation pathway on fibroblasts, parallels our observation of increased PAR-1 expression.

[0129] Benign proliferative disorders are characterized by a continuous basement membrane separating the epithelium from the stroma, similar to the normal tissue organization (Liotta et al., 1991). It is possible that the presence of a continuous basement membrane may actually quarantine any tumor-derived thrombin or trypsin from the stromal fibroblasts. Thus, the actions of thrombin and trypsin within the TME may be accentuated through up-regulation of PAR-1 and PAR-2 in the stromal fibroblasts as they de-differentiate (ie. SMA-negative to SMA-positive). The activation of PAR-1 and PAR-2 on tumor cells contributes to migration by increasing their adhesive properties as well releasing urokinase, both of which are early changes during the initiation of metastasis (Nierodzik et al., 1996; Nguyen et al., 1998; Evans et al., 1997).

[0130] We were able to mimic our in situ observations in vitro using cultured human dermal fibroblasts. Quiescent, SMA-negative, non-proliferating (Topo IIα-negative) cell cultures did not express detectable PAR-1 or PAR-2, similar to those of the stromal fibroblasts in normal and benign human tissues in situ. Most notably, we were able to mimic the transformation of PAR-1 and PAR-2-negative to PAR-1 and PAR-2-positive fibroblasts in vitro, after the quiescent cells were subjected to scrape wounding indicating that tissue damage relays a signal for PAR induction. In summary, this is the first in situ histological comparative report describing the presence of PAR-1 and PAR-2 protein and mRNA in human malignant tumor cells as well as in local mast cells, macrophages, endothelium and vascular smooth muscle cells of the TME. More importantly, we observed PAR-1 and PAR-2 immunolabeling in the stromal fibroblasts immediately surrounding the malignant cells which was absent in the surrounding stromal fibroblasts of the nonnal and benign breast epithelial cells. The presence of both PARs and their activating proteases within the TME suggests an autocrine and/or paracrine cascade in the processes of cellular metastasis, perhaps as natural mechanisms of tissue injury. It will be important to investigate if there is a correlation between the relative amounts of PAR-1 or PAR-2 in the tumors cells and in the stromal fibroblasts with tumor grade, and to expand our investigations into the expression of all of the members of the PARs into other pathological tissues. Since the degree of tumor cell malignancy has been classified by the amounts of secreted thrombin or trypsin, theoretically, the amounts of PAR-1 and PAR-2 in the TME cells may also be a valid predictor of metastatic activity, thereby acquiring diagnostic and prognostic value. More importantly, these data suggest attractive targets for therapeutic approaches, whereby PAR-1 and PAR-2 antagonists and anti-thrombin and anti-tryptase agents may be directed to disrupt some of the processes of cell metastasis.

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We Claim:
 1. A method of modifying the tumor cell microenviromnent to reduce or prevent the establishment, growth or metastasis of malignant cells that directly or indirectly activate the PAR-i receptor of normal cells comprising providing a pharmaceutically effective amount of a PAR-1 inhibitor and optionally a PAR-2 inhibitor to a patient with malignant cells that directly or indirectly activate PAR-1 and/or PAR-2.
 2. The method of claim 1 wherein the PAR-1 inhibitor is a compounds of the general formula:

wherein: R₁ is selected from amino, C₁-C₈ alkylamino, C₁-C₈ dialkylamino, arylarnino, arC₁-C₈ alkylamino, C₃-C₈ cycloalkylamino, heteroalkylC₁-C₈ alkylamino, heteroalkylC₁-C₈ alkyl-N-methylamino, C₁-C₈ dialkylamino C₁-C₈ alkylamino, -N(C₁-C₈alkyl)-C₁-C₈alkyl-N(C₁-C₈alkyl)₂, -N(C₁-C₈ alkyl)(C₁C-₈ alkenyl), -N(C₁-C₈alkyl)(C₃-C₈cycloalkyl), heteroalkyl or substituted heteroalkyl, wherein the substituent on the heteroalkyl is selected from oxo, amino, C₁-C₈ alkoxy, C₁-C₈ alkyl, C₁-C₈ alkylamino or C₁-C₈ dialkylamino; R₂ is selected from unsubstituted or substituted aryl, arC₁-C₈ alkyl, C₃-C₈cycloalkyl or heteroaryl, wherein the substituents on the aryl, aralkyl, cycloalkyl or heteroaryl group are independently selected from one or more of halogen, nitro, amino, cyano, hydroxyalkyl, C₁-C₈ alkyl, C₁-C₈ alkoxy, C₁-C₈alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl; R₃ is selected from H or C₁-C₈ alkyl; R₄ and R₅ are each selected from H, C₁-C₈ alkyl, amino C₁-C₈ alkyl, amidino C₁-C₈ alkyl, guanidino C₁-C₈ alkyl, aryl, aryl C₁-C₈ alkyl, substituted aryl, substituted arylC₁-C₈ alkyl, heteroaryl, heteroaryl C₁-C₈ alkyl, substituted heteroaryl, substituted heteroaryl C₁-C₈ alkyl, cyclo C₃-C₆ alkyl or substituted cycloC₃-C₆alkyl, wherein the substituents on the aryl, aralkyl, cycloalkyl or heteroaryl group are independently selected from one or more of halogen, nitro, amino, amidino, guanidino, cyano, hydroxyalkyl, C₁-C₈ alkyl, C₁-C₈ alkoxy, C₁-C₈ alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl; R₆ and R₇ are each selected from H, C₁-C₈ alkyl, amino-C₁-C₈ alkyl, amino-C₃-C₈ cycloalkyl, amidino C₁-C₈ alkyl, guanidino C₁-C₈ alkyl, aryl, substituted aryl, aryl C₁-C₈ alkyl, substituted aryl C₁-C₈ alkyl, heteroaryl C₁-C₈ alkyl or substituted heteroaryl C₁-C₈ alkyl, wherein the substituents on the aryl, aralkyl, cycloalkyl or heteroaryl group are independently selected from one or more of halogen, nitro, amino, amidino, guanidino, cyano, hydroxyalkyl, C₁-C₈ alkyl, C₁-C₈ alkoxy, C₁-C₈ alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl; Either R₅ or R₇ must be H when m is 1; in addition, when R₅ is H, then R₄ cannot be H; and, when R₇ is H, then R₆ cannot be H; R₈ is selected from H, C₁-C₈ alkyl, amino C₁-C₈ alkyl, allyl, C₃-C₈ cycloalkyl, substituted C₃-C₈ cycloalkyl, aryl, substituted aryl, ar C₁-C₈ alkyl, substituted ar C₁-C₈ alkyl, heteroaryl, substituted heteroaryl, heteroaryl C₁-C₈ alkyl or substituted heteroaryl C₁-C₈ alkyl, wherein the substituents on the aryl, aralkyl, cycloalkyl or heteroaryl group are independently selected from one or more of halogen, nitro, amino, amidino, guanidino, cyano, hydroxyalkyl, C₁-C₈ alkyl, C₁-C₈ alkoxy, C₁-C₈ alkoxycarbonyl, acetyl, fluorinated C₁-C₄ alkyl, fluorinated C₁-C₄ alkoxy or C₁-C₄ alkylsulfonyl; X is CH or N; n is an integer selected from 0, 1, 2 or 3; m is an integer selected from 0 or 1; p is an integer selected from 1 or 2; and pharmaceutically acceptable salts thereof.
 3. The method of claim 1 wherein the PAR-1 inhibitor is administered with a therapeutically effective amount of at least one PAR-2 inhibitor.
 4. The method of claim 2 wherein the PAR-1 inhibitor is administered with a therapeutically effective amount of a cytokine selected from the group consisting of IL-2, IL-12, IL-18, G-CSF, M-CSF, GM-CSF, INF-α, INF-β, INF-γ, TNF and combinations thereof.
 5. The method of claim 4 wherein additionally administered in a pharmaceutical effective amount is at least one conventional chemotherapy agent.
 6. The method of claim 5 wherein the chemotherapy agent is selected from the group consisting of antiangiogenic compounds, alkylating compounds, antimetabolites, hormonal agonist /antagonists, monoclonal antibodies for cancer treatment, antiproliferative compounds and combinations thereof.
 7. The method of claim 2 wherein additional administered are T cells selected from the group consisting of activated T cells, activated NK cells and combinations thereof.
 8. The method of claim 1 wherein the PAR-1 inhibitor is administered before surgery.
 9. The method of claim 1 wherein the PAR-1 inhibitor is administered after surgery.
 10. A method for the modulation of the immune system to enhance a patient's immune response to malignant cells that directly or indirectly activate the PAR-1 receptor of normal cells comprising administer a pharmaceutically effective dose of a PAR-1 inhibitor and optionally a PAR-2 inhibitor to the patient to enhance the patient's immune response to the malignant cells.
 11. The method of claim 10 wherein additionally administered are cytokines to facilitate the development of a Th1 response.
 12. The method of claim 11 wherein the cytokines are selected from the group consisting of IL-2, IL 12, IL-I18, INF-α, INF-β, INF-γ, TNF and combinations thereof.
 13. The method of claim 10 wherein additionally administered are T cells selected from the group consisting of activated CTL cells, activated NK cells and combinations thereof.
 14. The method of claim 10 wherein additionally administered are activated NK cells.
 15. The method of claim 10 wherein additionally administered are activated CTL cells.
 16. The method of claim 10 wherein the PAR-1 inhibitor is administered before surgery.
 17. The method of claim 10 wherein the PAR-1 inhibitor is administered after surgery. 